Connect WhatsApp to Microsoft Bookings — send reminders
Bridge Microsoft Bookings appointments to WhatsApp reminders via Google Calendar. Zellbox picks up every Bookings appointment and fires 24h + 2h WhatsApp reminders automatically.
by Nacho CollNacho founded Zellbox to give appointment-driven small businesses — clinics, salons, spas, physio, aesthetics, vets, mental-health, and fitness studios — a WhatsApp-first calendar and customer record system.
Editorial disclosure: I work at Zellbox. Microsoft Bookings described from their product page as of August 2026. Zellbox’s Microsoft 365 support may change; check the current docs before setup.
Microsoft Bookings handles booking inside Microsoft 365. Zellbox connects to Google Calendar as its calendar source — so the bridge for Microsoft Bookings → Zellbox WhatsApp is one extra hop via Zapier / Power Automate.
How it works
- In Microsoft Bookings → Booking Page → confirm appointments write to the staff Outlook calendar.
- In Zapier (or Power Automate) → create a flow: new Outlook Calendar event → create matching Google Calendar event.
- In Zellbox → Onboarding step 2 → connect the destination Google Calendar.
- Every Microsoft Bookings appointment now propagates → Google Calendar → Zellbox WhatsApp reminder.
What Zellbox adds
- WhatsApp channel — Microsoft Bookings sends email and optional SMS natively, but WhatsApp isn’t a Microsoft 365 feature at all; the Outlook-to-Google-Calendar bridge is what makes a WhatsApp reminder possible.
- Signed consent PDFs for services requiring them — the signed PDF attaches to the customer record automatically, something Bookings’ own reminder flow doesn’t produce.
- Two-way replies land in your Zellbox inbox — when a client replies to confirm or ask a question, the message shows up next to that client’s record instead of on a staff member’s personal phone.
Zapier vs Power Automate for the Outlook bridge
Zapier: simpler to set up
Zapier’s Outlook Calendar trigger is quick to configure and works fine for the 24h reminder window, since it just needs to catch a new appointment sometime before the following day.
Power Automate: closer to real-time
Because Microsoft Bookings writes directly to the staff Outlook calendar, Power Automate (native to Microsoft 365) can pick up new or changed appointments faster than Zapier’s polling interval — worth the extra setup if your practice handles frequent same-day Bookings changes and relies on the 2h reminder being accurate.
Feature summary
| Zellbox layer | Microsoft Bookings built-in | |
|---|---|---|
| Booking in Microsoft 365 | via Bookings | Native |
| Email + SMS reminders | Not the focus | Native |
| WhatsApp reminders | Native + free tier | Not available |
| Signed consent PDFs | Native | Custom intake form |
Bridge adds ~15 min to setup; then runs unattended.
About the author: Nacho Coll is the founder of Zellbox. He writes about WhatsApp Business automation for appointment-driven small businesses.
Frequently asked questions
How does Microsoft Bookings connect to WhatsApp via Zellbox?
Does Zellbox connect directly to Microsoft 365?
Is this worth the setup?
About the author
Nacho Coll
Founder & Engineer at Zellbox
Nacho founded Zellbox to give appointment-driven small businesses — clinics, salons, spas, physio, aesthetics, vets, mental-health, and fitness studios — a WhatsApp-first calendar and customer record system. Writes about WhatsApp Business automation, no-show economics, recall-cycle playbooks, and the operational realities of running visit-driven businesses at scale.
